code: def _read_sample(self, index: int) -> Tuple[Any, Any]:
      raise NotImplementedError
  
file_path: doctr/doctr/datasets/datasets/base.py
imports: import os
  import shutil
  from pathlib import Path
  from typing import Any, Callable, List, Optional, Tuple, Union
  import numpy
  from doctr.io.image import get_img_shape
  from doctr.utils.data import download_from_url
  from ...models.utils import _copy_tensor
label_desc: Use image node_id 3 for calling the _AbstractDataset obj's underlying member method code with example usage: obj._read_sample(index) without return types